This disclosure relates generally to the field of image processing. More particularly, but not by way of limitation, this disclosure relates to a technique for converting a three-dimensional (3D) mesh representation of an object into a two-dimensional (2D) representation in a memory efficient manner. This disclosure further describes a novel mechanism by which an operation on a 2D representation of an object can quickly and efficiently be mapped to the object's corresponding 3D representation.
It is known that some types of operations applied directly to a 3D model are difficult to perform. One class of functions this characterization applies to are operations that filter elements across a seam. Here filtering may be taken as any function that relies on pixel values that are to each side of a seam. For example, a blur operation. For this reason, many “3D operations” are actually applied to a 2D image representation (e.g., in memory) of an object's 3D representation; the results are then mapped back onto the 3D model's surface. Conformal or UV mapping is often used to model the correspondence between a point on a 3D surface and a 2D memory location. Conceptually, conformal or UV mapping corresponds to the cutting of a 3D object's surface along seams which allow the (cut) surface to be laid flat (with varying amounts of distortion). One well-known example of this is the Mercator projection of the earth. Conformal mapping techniques are often wasteful of memory and do not lend themselves to cross-seam operations.